13. Krebs Cycle and ETC require oxygen to occur, making them?

Acetyl CoA is produced during the process of Krebs cycle in the presence of oxygen.

Explanation:

Krebs cycle is also called citric acid cycle. This process is used by living organisms for the release of energy from food molecules in the process of aerobic respiration. In this chemical reaction, oxidation of acetyl-CoA occurs which is obtained from food molecules such as carbohydrates, proteins and lipids. When oxidation of food molecules occurs, energy is released in the form of Adenine tri phosphate (ATP) and carbondioxide gas is produced.